A Liquid Crystal Display (LCD) is a flat-panel display. With the development of science and technology, electronic products containing LCDs are developed to be light-weight, thin, short and compact, and have advantages such as right-angle displays, low power consumption, a small size, and being free of radiation, which can allow users to enjoy the best visual environment.
A display having a touch sensing function is derived from technology for function diversity, and common touch technology includes in-cell touch technology and on-cell touch technology. The in-cell touch technology refers to embedding a touch sensing function into liquid crystal pixel circuitry, while the on-cell touch technology refers to embedding a structure for the touch sensing function between a color filter substrate and a polarizing plate. The in-cell touch technology makes the display thinner and thus arouses more attention.
FIG. 1 shows an array substrate having a touch sensing function in the related art. The array substrate includes, from bottom to top, a base 111; a polycrystalline silicon layer 112 formed on the base 111; a coated gate insulation layer 113; a first metal layer, in which gate electrodes 114 of thin film transistors (TFTs) and scan lines are formed by a patterning process; an interlayered insulation layer 115 covering the patters in the first metal layer; a second metal layer, in which source electrodes 116, drain electrodes 125 of the TFTs and data lines are formed by the patterning process; a planarization layer 118; a third metal layer (M3) formed on the planarization layer 118, where touch wirings 119 are formed in the third metal layer by the patterning process; a first insulation layer 120; touch sensing electrodes 121 formed on the first insulation layer 120, where the touch sensing electrodes 121 can also operate as common electrodes; a second insulation layer 122; a first via hole 123 formed by etching the second insulation layer 122, the first insulation layer 120 and the planarization layer 118, and a second via hole 124 formed by etching the second insulation layer 122 and the first insulation layer 120; and a pixel electrode 117 formed on the second insulation layer 122 and electrically connected with the drain electrode 125 of the thin film transistor through the first via hole 123, where a bridge structure is formed by the material of the pixel electrode, to electrically connect the touch sensing electrode 121 to the touch wiring 119 through the second via hole 124.
However, in the array substrate formed as above, the touch wiring is formed on the planarization layer, thus the surface of the film layer on the touch wiring is not flat, thereby severely affecting the effect of the subsequent rubbing process, and easily leading to light leakage at both sides of the touch wiring.